A 16 week radomized, blinded, placebo controlled, parallel study w enrollment of approximately 150 subjects into 3 treatment groups (10mg and 20 mg r-met-HuLeptin and matched placebo [placebo pooled for analysis]). Eligible subjects will be randomized 91:1 ratio to one of the following two dose schedules: - 10mg r-met-HuLeptin/placebo injection given subcutaneously, one daily (QD in the morning); - 10mg r-met-HuLeptin/placebo injection given subcutaneously twice daily (BID in the morning and evening). Within each dose schedule subjects will be randomly allocated to r-met-HuLeptin or placebo in a 2:1 ratio. A minimization procedure will be used to balance the treatment groups at baseline for hemoglobin A (<10%and >10%). Subjects will receive blinded treatment for 16 weeks which may be followed by an open label maintenance study.